Polymeric detergents



Patented Nov. '23, 1948 UNITED STA-res f PATENT OFFICE POLYMERICDETERGENTSQ Louis E. Book, Huntingdon Valley, and James L. Rainey,Abington, Pa., assignors to Rohm & Haas Company, Philadelphia, -Pa., acorporation of Delaware No Drawing 6 Claims.

7 This invention relates to surface-active or capillary-active agents.It relates to'the preparation, of materials which have high detergent inthe form of micelles. While the exact nature of such micelles is notestablishedLthere is evidence that they are electrically chargedaggregates of molecules. For example, when a sodium soap of a fatty acidis dispersed in water, it dissociates into positively charged sodiumions and into negative ions. Some of the latter apparently formaggregates with soap molecules and, as a result, negatively chargedmicellesare produced.

Application September 9, 1944, Serial No. 553,477

higher cost of synthetic detergents combines to make the use of suchdetergents uneconomical and ofteni'mpractical. Furthermore,the'materials are inefiective in many laundering operations whereinextremely hot water is used in order to accelerate the removal of soil.

The products of this invention diflfer fromand have advantagesover-detergents known heretofore in that their effectiveness is notdependent upon the formation of loosely bound micelles. By

f the process of .this invention, water-soluble macromolecules aresynthesized in which all of the bonds between atoms are primary valencelinks and, hence, are strong and are not affected by such factors asconcentration and temperature.

Furthermore, the synthesized macromolecules Because the micelles carry anegative charge, this I type of soap is known as an anion-activedetergent; In contrast, detergents of the type of quaternary ammoniumcompounds yield positively charged micelles in aqueous solution and,hence, are known as cation-active soaps or agents. This conception ofthe formation of micelles is based on measurements of freezing points,vapor pressures, and electrical conductivities of aqueous dispersions ofsurface-active agents. It is further recognized that surface activity isrelated to the formation 'of such micelles and to the orientatio of themicelles at an interface.

The individual molecules in colloidal micelles are held together only byphysical forces or by weaksecondary valences; and,-as a result, the

extent of micelle formation depends upon the prevailing conditions, andit is affected by such factors as the concentration of thesurface-active agent, the presence of electrolytes, solvents, and othersurface-active agents, and also upon the temperature. Thus, dilution ofthe solution, elevation ofthe temperature, or a change in the amount ofany salts which may also be present in solution favor the reversion ofmicelles into a and, as a result, detergency is lost. The necessity ofusing relatively high concentrations plus the contain balancedhydrophilic and hydrophobic groups so positioned in the macromoleculethat .orientation can and does occur readily at an interface.

The products of this invention may be made by condensinghydrocarbon-substituted phenols-with formaldehyde to produce polymericmaterials which are in fact macromolecules and then introducing intosaid macromolecules hydrophilic groups. The hydrophilic groups, whichimpart water solubility, may be ether-alcohol groups or esterlfiedether-alcohol groups and are introduced, for example, by the reaction ofethylene oxide or a propylene oxide or a butylene oxide with themacromolecule. If desired, the terminal hydroxyl of said ether-alcoholgroup may be converted into a salt-forming ester group of a polybasicacid. v

The resultant products may be considered to have three functionalportions. Thus, they contain (a) as the hydrophobic portion, thehydrocarbon'groups attached to the phenol nucleus; (b) as thehydrophilic portion, the modified or unmodified ether-alcohol groups,and (c) as .the polymeric portion, the phenol nuclei joined bymethylene. bridges. The hydrocarbon groups attached to the phenol andthe modified or unmodifled ether-alcohol groups also attached tothephenol are so balanced as to assure water solubility and orientation. atan interface. At the same time, the polymeric nature of the productassures such a, high molecular weight, that the product is in fact amacromolecule which imparts capillaryor surface-activity to a solution,as do micelles of ordinary soaps, but which is stable and is notdissociated as are the micelles of customary detergents under adverseconditions.

The above discussion isfor purposes of theoretical explanation only, andit must be understood that the so-called three portions of themacromolecule are not independent of each other tached to the phenolnucleus may vary as to kind but in every case must contain at least fourcarbon atoms. In reality, substituting groups of at least eight carbonatoms are much preferred. Generally, it is preferred that thesubstituent hydrocarbon group be a straight or branched chain acyclicgroup, such as n-butyl, iso-butyl, tertiary butyl, amyl, tertiary amyl,n-octyl, diisobutyl, decyl, dodecyl, hexadecyl, octadecyl, and the like.Alternatively, phenols substituted with alicyclic groups may be used.These are typified by cyclohexyl phenol, methyl-cyciohexyl phenol,butyl-cyclohexyl phenol, and dicyclohexyl phenol. While aryl-substitutedphenols, such as p-phenyl phenol and p-naphthyl phenol, may be employedthey are less satisfactory than those listed above unless they in turncontain an alkyl group. Thus, p-tolyl phenol is much preferred overp-phenyl'phenol. Furthermore, a preference is given to thepara-substituted phenols over those substituted in the ortho position.It .is understood that although it is preferable to employ individualphenols, mixtures of phenols, for example, p-tert.-amylandp-diisobutylphenols, may be employed.

The ratio of formaldehyde should be between 0.5 and 1.0 mol per mol ofphenol. The formaldehyde may be used in the form of a solution, such asthe formalin of commerce, or in a polymeric form such asparaformaldehyde. Also, though not preferred, it may be in a form suchas a formal or hexamethylene tetramine which will yield formaldehydeunder the conditions of reaction.

Ordinarily, the substituted phenol and formaldehyde are reacted bycondensing together in the presence of an acidic or alkalinecondensation catalyst until the products have become relatively viscous.Solvents may be employed. Acidic condensation catalysts are preferredbecause of the ease with which the condensation may be controlled.Elevated temperatures naturally accelerate the rate of reaction.Condensation of formaldehyde and substituted phenols such as are hereinvolved do not proceed to the infusible stage and, accordingly, nolimit, need be imposed upon the degree of condensation. In practice, itis convenient to follow the extent of condensation by means of viscositymeasurements and the condensation may be halted at an early stage atwhich the molecular weight is low and the product on the average has nomore than three or four phenolic units per molecule, or it maybecontinued until each macromolecule contains many more units. Thecondensation products may range in physical properties from oils tobrittle solids, depending upon the degree of condensation and the natureof the substituent hydrocarbon group on the phenol.

Polymeric detergents in which the hydrophilic or water-solubilizing'groups are ether-alcohols or derivatives thereof are the subjects ofother applications, Serial Nos. 553,476, 553,478, 553,479, and 553,480,filed of even date. v

The polymeric detergents of this invention have as their hydrophilicgroups the salt-forming partial esters of (a) polymerichydrocarbon-substituted phenoxy alcohols and (b) mineral acids from thegroup consisting of sulfuric and phosphoric acids. The polymericalcohols from W it-=11 4 the esters are prepared may be made in variousways, shown in detail in application Serial No. 553,476, filed of evendate. Alkylene oxides, such as ethylene oxide, a propylene oxide, or abutylene oxide, may be condensed with a substituted phenol-formaldehydemacromolecule. The condensation is preferably conducted in the presenceof an alkaline catalyst, such as a hydroxide of an alkali metal,although in some instances no catalyst is required. While this reactionmay be carried out at lower temperatures and at atmospheric pressure inthe presence of solvents, it is preferred to conduct it at temperaturesabove C. under superatmospheric pressure with or without solvents. Oneor more mols of the alkylene oxides may be reacted per mol of phenolcondensed in the macromolecule. When one mol is reacted, a simplealkylol group, ROH, becomes attached, through the oxygen atom of thephenol, to the phenol nucleus of the macromolecule. Such compounds havethe general formula:

OROH OROH fi J i I in which R is a hydrocarbon substituent of at leastfour carbon atoms, R is an alkylene group, and :r is an integer greaterthan one.

When, however, more than one mol of alkylene oxide is used, the groupwhich becomes attached to the phenolic nucleus is an ether-alcoholgroup, and the product may be represented as follows:

and the like. This reaction is also preferably conducted in the presenceof an alkaline catalyst.

The alcohols described above may be esterified with polybasic acids ortheir equivalents such as the anhydride. Polycarboxylic organic acids,such as adipic and phthaiic, are operable as are inorganic polybasicacids, particularly sulfuric and phosphoric acids. When esterificationtakes place between the alcohols and the polybasic acids, there remainunreacted or free acid groups which may then be neutralized to producesalts. It is preferred to neutralize the partial esters of the acidswith the hydroxides, carbonates, bicarbonates, or oxides of the group I(alkali) metals or group II (especially alkaline earth)- metals whichproduce water-soluble products. Obviously, salts of the heavy metals canbe prepared in the same way. The final product, which is prefrablywater-soluble, is in reality a salt of a halfflux condenser was chargedthe tives have the following generali'ormulas:

' 1: G am i.

C(RO) ,.-POs.Ma

, tures of sulfuric and phosphoric acids or equivalents may be used.

The products may tive polymeric products of highmolecularweightcontaining in their chemical structure salt-form lngpartial esters of (a) inorganic polybasic acids from the groupconsisting of sulfuric andf D1108! (b) hydrocarbon-substiti1te(i vphenoxy alcohol units in which the hydrocarbon phoric acids, and

substituent contains at least four said phenoxy alcohol carbon atoms,

Following are examples which indicate the i'erred method of preparingthe products .of this invention.

' Example 1 Step 1.Into a three-necked withthermometer, mechanicalagitator, androfollowing: 412 grams of diisobutylphenol(a,u,y,'y-tetramethylbutylphenol), 162 grams-of a 37% aqueous solutionof formaldehyde, and 27.6 grams of water. The mixture was agitated andheated to a temperature of 90 C. At this point," 2.46 grams of oxalicacid and 0.92 gram oi Twitchells reagent dissolved in ten grams. ofwater were added. While being agitated, the reaction mixture wasrefluxed for six hours. Two hundred grams of water and 384 grams oftoluene were added. and refluxing was continued for an hour. Agitationwas stopped and the contents of the flask were removed to a separatoryfunnel. The aqueous and resinous layers were separated and the sol.-vent was removed from the resinous layer by vacpotassium, or lithium, orone equivaalkaline earth (group 11) metal such' be described assurface-ace. cof

units being Joined by means of methylene bridges.

solution ha ngfsclids content or 78.1%and a hydroxyl number oi .118. g io Step 3.--'1o 233 parts oi this solution was then added, dropwlse, 65parts of 98% H2804. The solution was stirred and maintained at atemperature 01' 45 0. during the addition of the acid. The temperaturewas raised to SIP-40 0., and the mixture was stirred continuously forthree and a half hours, after which 500 parts of'toluene was added tothe viscous product. The resultant solution was then poured slowly into300 parts of a 10% aqueous solution of NaOl-I. and the mixture wasstirred until it became uniiorm.- This mixture was then steam-distilledand evaporated in vacuo in order to remove the toluene. .The dualproduct was prepared as an 18% solution in water. Assuch. it was aviscous, gelatinous paste which gave foaming solutions on furtherdilution with water. The formula of the product may be represented asfollows:

owlmotsoine oa zirnoiisolire n on I q Inn v Example 2 r To a mixture rits parts of the intermediate ethylene oxide addition product from step2 of Example 1 (co 7 o to approximately 0.36 mol r dilsobutylphenol) and95 parts additional toluene was added 83parts of phosphorus pentflaskequipped uum distillation. After the removal of the sol-' vent, heatingat a reduced pressure of 1.5 to 2.5

mm. and at a temperature of 245 to 250 C. was

of ethylene oxide, and the with stirring for one hour was treated with220 oxide 1 in portions while the temperature was maintained at 15 C.Thirty-eight parts oi',98% sulfuric acid was then added. dropwise. whilethe temperature was maintained at 20-45 O. After iour'and one-half hoursof stirring at 4045 6., the sulfatedmixture was neutralized bypourin'git into a solution of 77 parts of NaOH in 300' parts of' water. Toluenewas removed by steam distillation. The product was a viscous paste.Dilution to 10% solids gave a clear, geiatinous-solution which had gooddetergent properties.

- Example 3 Step 1.'An octadecyl, phenol-formaldehyde condensate wasprepared .by heating a mixture of 348 parts (1.0 mol) of octadecylphenol, 81 parts (1.0 mol) of 37% formaldehyde, 18.8 parts ofwater,-1.23 parts of oxalic acid, and 0.46 part of Twitchells reagentfor sevenhours under reflux.- One hundred ninety-two parts of tolueneand partsof water were added, and refluxing wascontinued for one-halfhour. The aqueous layer was withdrawn and the toluene layer concentratedby removal of toluene under reduced pressure. The residue was finallyheated for flve hours at 250 C. at a pressure of 1.5 mm. of mercury. Theproduct was a soft. viscous material, insoluble in water and having ahydroxyl number of 144 and a viscosity of 1.0 poise when measured as a60% solution in toluene.

Step 2.One hundred ei hty parts of octadecylphenol-formaldehydecondensate (corresponding to approximately 0.5 'moi 'of octadecylphenol)parts (5.0 mols) of ethylene oxide in the. manner described in Example1.

aviscous.

The product, which contained about ten oxyethylene groups peroctadecylphenol residue, had a corrected hydroxyl number of 85.-

Step 3.--The product of step 2 was phosphated and sulfated as shown inExample 2 and was found to have very good detergent properties at lowand high temperatures, even in very hard water.

Although the above examples are directed to the use of ethylene. oxide,it is understood that a propylene oxide or a butylene oxide may beemployed in a similar manner. the hydrophilic' group is increased, theproduct ordinarily becomes more water-soluble. It is,

therefore, advisable to increase the hydrophobic group proportionately.'This can be done by increasing the size of the hydrocarbon substituentof the phenol, as represented by R. in the above general formula. Inthis way, a balance is maintained between the hydrophilic andhydrophobic portions of the macromolecule so that the product iswater-soluble and at the same time capilla'ry-active.

All of the products of this invention function as capillary-active orsurface-active agents. As such, they become oriented at an interface,lower the surface tension of water, and cause more rapid wetting ofsurfaces such as the surfaces of fibers as measured by the standardDraves Sinking Test. Their outstanding property is their eifectivenessas detergents. In this capacity, as measured by we sh tests andlaundering tests, they are outstanding and are far superior to soaps andsynthetic detergents known heretofore.

As detergents the products described herein may be used in hard water orin water of high salt content. They may be employed under acidic oralkaline conditions. Their advantage over synthetic detergents residesin the fact that they are not micellar but are in fact macromoleculeswhich do not revert as do micelles. Thus, they are excellent detergentsat very low concentrations or at very high temperatures where formersynthetic detergents failed.

They are uncommonly advantageous in the laundering of cotton fabrics andin the scouring 'of'wool, sized, dyed, and printed fabrics in general.They may be used for preparing dispersions of oil in water ordispersions of polymerizable materials prior to the polymerizationthereof. Also, they serve to break water-in-oil emulsions such as areencountered in oil-fields. And they have been found to be verysatisfactory in the treatment of leather, in the dispersion of pigments,and as assistants in dyeing.

The products of this invention are particularly As the length of 8 and(bl'from 0.5 to 1.0 mole of formaldehyde, then reacting therewith (c)from one to twentyone moles of an alkylene oxide from the classconsisting of ethylene oxide, propylene oxide, and

butylene oxide, then ((1) esterifying the resultant alcohol with onemole of a polybasic acid from.

the class consisting of sulfuric and phosphoric acids, and finally (e)neutralizing the product of esterification to form therefrom a salt of ametal from the class consisting of alkali and alkaline earth metals. 7

2. Water-soluble polymeric detergents formed by condensing by heating(a) one mole of a phenol from the class consisting of ortho-substitutedand para-substituted phenols, said phenol having'the formula in which Ris a saturated hydrocarbon substituent containing eight to eighteencarbon atoms and (b) from 0.5 to 1.0 inoleof formaldehyde,

' then reacting therewith (c) from one to twentyone moles of an alkyleneoxide from the class consisting of ethylene oxide, propylene oxide, andbutylene oxide, then (d) esterifying the resultant alcohol with one moleof sulfuric acid, and finally (e) neutralizing the product ofesterification to form therefrom a salt of a metal from the classconsisting of alkali and alkaline earth metals.

3. Water-soluble polymeric detergents formed by condensing by heating(a) one mole of a phenol from the class consisting of ortho-substitutedand para-substituted phenols, said phenol having the formula in which R'is a saturated hydrocarbon substituent containing eight to eighteencarbon atoms and (b) from 0.5 to 1.0 mole of formaldehyde, then reactingtherewith (c) from one to twenty-one moles of an alkylene oxide from theclass consisting of ethylene oxide, propylene oxide, and butylene oxide,then (d) esterifying the resultant alcohol with one mole of phosphoricacid, and finally (e) neutralizing the product of useful when used inconjunction with other capillary-active agents, including fatty acidsoaps and synthetic detergents such as those shown in United StatesPatents 2,115,192 and 2,143,759. Such combinations have extraordinarilyhigh degrees of wetting and detergent properties.

We claim:

1. Water-soluble polymeric detergents formed by condensing by heating(a) one mole of a phenol from the class consisting of ortho-substitutedand para-substituted phenols, said phenol having the formula in which Ris a saturated hydrocarbon substituent containing eight to eighteencarbon atoms esterification to form therefrom a salt of a metal from theclass consisting of alkali and akaline earth metals. v 1

4. Water-soluble polymeric detergents formed by condensing by heating(a) one mole of a phenol from the class consisting of ortho-substitutedand para-substituted phenols, said phenol having the formula ing (a) onemol of octyl phenol having the formula C'HUG O H formula Caller-60H and(b) from 0.5 to 1.0 mol of formaldelwde,

then reacting therewith (c) from one to twentyone mols of ethyleneoxide, then (d) esterifying the resultant alcohol with one mol of apolybasic 10 acid from the group consisting of sulfuric and phosphoricacids, and finally (e) neutralizing the product of esteriflcation toform therefrom a salt of sodium.

LOUIS H. BOCK. JAMES L. RAINEY.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES TS Number Name Date 1,917,250 Harris July 11, 19331,917,257 Harris July 11, 1933 2,046,318 Brubaker July 7, 1936 2,076,624DeGroote Apr. 13, 1937 OTHER REFERENCES ClaytonTheory of Emulsions,published by Blakiston Company, Philadelphia, Pa., 4th edition (1943),page 127.

